Techniques and apparatuses for downlink control channel design using a top to bottom search space

ABSTRACT

User equipment associated with a legacy network may utilize a bottom-to-top search technique to identify relevant control channel samples. Generating a control channel that is configured for the bottom-to-top search technique may lead to poor performance in a single-carrier waveform, which may be disadvantageous as networks move toward New Radio. In some aspects, described herein, a base station generates a control channel that is configured to minimize gaps in the control channel, and a user equipment performs a top-to-bottom search technique to identify relevant control channel samples. By using the top-to-bottom search technique, degradation of single-carrier waveforms is reduced and efficiency is improved.

CROSS-REFERENCE TO RELATED APPLICATIONS UNDER 35 U.S.C. § 119

This application is a continuation of U.S. patent application Ser. No.17/822,518, filed on Aug. 26, 2022, entitled “TECHNIQUES AND APPARATUSESFOR DOWNLINK CONTROL CHANNEL DESIGN USING A TOP TO BOTTOM SEARCH SPACE,”which is a continuation of U.S. patent application Ser. No. 16/711,768,filed on Dec. 12, 2019 (now U.S. Pat. No. 11,463,188), entitled“TECHNIQUES AND APPARATUSES FOR DOWNLINK CONTROL CHANNEL DESIGN USING ATOP TO BOTTOM SEARCH SPACE,” which is a divisional of U.S. patentapplication Ser. No. 15/873,441, filed on Jan. 17, 2018 (now U.S. Pat.No. 10,511,399), entitled “TECHNIQUES AND APPARATUSES FOR DOWNLINKCONTROL CHANNEL DESIGN USING A TOP TO BOTTOM SEARCH SPACE,” which claimspriority to Provisional Application No. 62/483,269, filed on Apr. 7,2017, entitled “TECHNIQUES AND APPARATUSES FOR DOWNLINK CONTROL CHANNELDESIGN USING A TOP TO BOTTOM SEARCH SPACE,” the contents of which areincorporated herein by reference in their entireties.

BACKGROUND Field

Aspects of the present disclosure generally relate to wirelesscommunication, and more particularly to techniques and apparatuses fordownlink control channel design using a top to bottom search space.

Background

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power, and/or the like). Examples of such multiple-accesstechnologies include code division multiple access (CDMA) systems, timedivision multiple access (TDMA) systems, frequency-division multipleaccess (FDMA) systems, orthogonal frequency-division multiple access(OFDMA) systems, single-carrier frequency-division multiple access(SC-FDMA) systems, time division synchronous code division multipleaccess (TD-SCDMA) systems, and Long Term Evolution (LTE).LTE/LTE-Advanced is a set of enhancements to the Universal MobileTelecommunications System (UMTS) mobile standard promulgated by theThird Generation Partnership Project (3GPP).

A wireless communication network may include a number of base stations(BSs) that can support communication for a number of user equipment(UEs). A UE may communicate with a BS via the downlink and uplink. Thedownlink (or forward link) refers to the communication link from the BSto the UE, and the uplink (or reverse link) refers to the communicationlink from the UE to the BS. As will be described in more detail herein,a BS may be referred to as a Node B, a gNB, an access point (AP), aradio head, a transmit receive point (TRP), a new radio (NR) BS, a 3GNode B, and/or the like.

The above multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless communication devices to communicate on a municipal,national, regional, and even global level. New radio (NR), which mayalso be referred to as 3G, is a set of enhancements to the LTE mobilestandard promulgated by the Third Generation Partnership Project (3GPP).NR is designed to better support mobile broadband Internet access byimproving spectral efficiency, lowering costs, improving services,making use of new spectrum, and better integrating with other openstandards using orthogonal frequency division multiplexing (OFDM) with acyclic prefix (CP) (CP-OFDM) on the downlink (DL), using CP-OFDM and/orSC-FDM (e.g., also known as discrete Fourier transform spread OFDM(DFT-s-OFDM)) on the uplink (UL), as well as supporting beamforming,multiple-input multiple-output (MIMO) antenna technology, and carrieraggregation. However, as the demand for mobile broadband accesscontinues to increase, there exists a need for further improvements inLTE and NR technologies. Preferably, these improvements should beapplicable to other multiple access technologies and thetelecommunication standards that employ these technologies.

A BS may convey control information to a UE on a control channel. Forexample, the control channel may include a physical downlink controlchannel (PDCCH) and/or the like. In some cases, a BS may provide controlinformation for multiple, different UEs on the PDCCH. For example, theBS may provide a cell that covers a group of UEs, and may providerespective sets of control channel elements (CCEs) for each UE, of thegroup of UEs, on the PDCCH. A set of CCEs for a particular UE isreferred to herein as a control resource set, or coreset. In such acase, each coreset may be encoded using a respective seed (e.g., arandom seed) corresponding to each UE. A UE may then search the PDCCHfor the coreset that corresponds to the UE, and may decode the coresetbased at least in part on the respective seed. For example, a UE mayiteratively attempt to decode candidate samples until the UE finds acorresponding candidate sample that includes the coreset.

A UE may search within a respective search space for the correspondingcoreset. For example, in a legacy network, such as LTE, the PDCCH may bearranged in a particular fashion, with a common region that all UEsmonitor and one or more UE-specific regions that are monitored bycorresponding UEs. A UE may blindly search within the common region anda corresponding UE-specific region. For example, the UE may attempt todecode candidate samples until the UE finds a candidate sample that canbe successfully decoded by the UE to obtain the corresponding coreset.The above approach may be referred to as a bottom-to-top searchtechnique. The bottom-to-top search technique may work well in LTEnetworks, but may pose certain problems in 3G/NR networks, especially ina millimeter wave (mmWave) deployment. For example, gaps betweencoresets (or candidate samples) may be common when a BS generates thePDCCH based at least in part on such a bottom-to-top search technique,which may degrade the single-carrier properties of the 3G/NR carriersignal. Furthermore, in mmWave deployments, a BS may be likely to covera smaller quantity of UEs than in a legacy network, so the bottom-to-topsearch technique may be inefficient in such situations, in addition tocausing detriment to the single-carrier properties of the 3G/NR carriersignal.

SUMMARY

Techniques and apparatuses, described herein, enable generation of aPDCCH to minimize gaps in the PDCCH, and enable a UE to search forrelevant control information based at least in part on a top-to-bottomsearch space. For example, when a BS covers a single UE, the BS maygenerate a candidate sample or coreset for the UE that occupies anentirety of a PDCCH provided by the BS. The UE may perform the blindsearch in a top-to-bottom fashion (e.g., searching for a candidatesample spanning the entirety of the PDCCH, then searching for candidatesamples on subsets of the PDCCH). Thus, the BS avoids degradation of thesingle-carrier waveform due to gaps between candidate samples whenserving a single UE. This may be particularly useful for mmWave, sincemmWave BSs are more likely to cover a single UE than other types of BSs.Furthermore, techniques and apparatuses described herein enableprovision of control information for multiple UEs using a PDCCH that isgenerated to minimize gaps and that is searchable using thetop-to-bottom search space, which improves efficiency and reducesdegradation of the single-carrier waveform for the multiple UEs.

In an aspect of the disclosure, a method, an apparatus, a base station,and a computer program product are provided.

In some aspects, the method may include receiving, by user equipment(UE), a control channel that includes a plurality of candidate sampleshaving at least two aggregation levels; scanning, by the UE, a set ofcandidate samples, of the plurality of candidate samples, to identify arelevant sample associated with the UE, wherein the scanning isperformed on the set of candidate samples in an order from a higheraggregation level of the at least two aggregation levels to a loweraggregation level of the at least two aggregation levels; and decoding,by the UE, the relevant sample.

In some aspects, the apparatus may include a memory and at least oneprocessor coupled to the memory. The at least one processor may beconfigured to receive a control channel that includes a plurality ofcandidate samples having at least two aggregation levels; scan a set ofcandidate samples, of the plurality of candidate samples, to identify arelevant sample associated with the apparatus, wherein the scanning isperformed on the set of candidate samples in an order from a higheraggregation level of the at least two aggregation levels to a loweraggregation level of the at least two aggregation levels; and decode therelevant sample.

In some aspects, the apparatus may include means for receiving a controlchannel that includes a plurality of candidate samples having at leasttwo aggregation levels; means for scanning a set of candidate samples,of the plurality of candidate samples, to identify a relevant sampleassociated with the apparatus, wherein the scanning is performed on theset of candidate samples in an order from a higher aggregation level ofthe at least two aggregation levels to a lower aggregation level of theat least two aggregation levels; and means for decoding the relevantsample.

In some aspects, the computer program product may include anon-transitory computer-readable medium storing computer executablecode. The code may include code for receiving a control channel thatincludes a plurality of candidate samples having at least twoaggregation levels; code for scanning a set of candidate samples, of theplurality of candidate samples, to identify a relevant sample associatedwith the device, wherein the scanning is performed on the set ofcandidate samples in an order from a higher aggregation level of the atleast two aggregation levels to a lower aggregation level of the atleast two aggregation levels; and code for decoding the relevant sample.

In some aspects, the method may include generating, by a base station,at least one control signal for at least one UE for transmission in acontrol channel, wherein the control channel is associated with aplurality of aggregation levels; selecting, by the base station, atleast one aggregation level, of the plurality of aggregation levels, forthe at least one control signal to minimize gaps in the control channel;and providing, by the base station, the control channel including atleast one sample corresponding to the at least one control signal.

In some aspects, the apparatus may include a memory and at least oneprocessor coupled to the memory. The at least one processor may beconfigured to generate at least one control signal for at least one UEfor transmission in a control channel, wherein the control channel isassociated with a plurality of aggregation levels; select at least oneaggregation level, of the plurality of aggregation levels, for the atleast one control signal to minimize gaps in the control channel; andprovide the control channel including at least one sample correspondingto the at least one control signal.

In some aspects, the apparatus may include means for generating at leastone control signal for at least one UE for transmission in a controlchannel, wherein the control channel is associated with a plurality ofaggregation levels; means for selecting at least one aggregation level,of the plurality of aggregation levels, for the at least one controlsignal to minimize gaps in the control channel; and means for providingthe control channel including at least one sample corresponding to theat least one control signal.

In some aspects, the computer program product may include anon-transitory computer-readable medium storing computer executablecode. The code may include code for generating, by a base station, atleast one control signal for at least one UE for transmission in acontrol channel, wherein the control channel is associated with aplurality of aggregation levels; selecting, by the base station, atleast one aggregation level, of the plurality of aggregation levels, forthe at least one control signal to minimize gaps in the control channel;and providing, by the base station, the control channel including atleast one sample corresponding to the at least one control signal.

Aspects generally include a method, apparatus, device, system, computerprogram product, non-transitory computer-readable medium, userequipment, wireless communication device, base station, and processingsystem as substantially described herein with reference to and asillustrated by the accompanying drawings and specification.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purpose ofillustration and description, and not as a definition of the limits ofthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is diagram illustrating an example of a wireless communicationnetwork.

FIG. 2 is a diagram illustrating an example of a base station incommunication with a UE in a wireless communication network.

FIG. 3 is a diagram illustrating an example logical architecture of adistributed radio access network (RAN).

FIG. 4 is a diagram illustrating an example physical architecture of adistributed RAN.

FIG. 5 is a diagram illustrating an example of a top-to-bottom searchspace for control resource sets in New Radio.

FIGS. 6A-6D are diagrams illustrating examples of providing downlinkcontrol information to one or more UEs using a top-to-bottom searchspace.

FIG. 7 is a flow chart of a method of wireless communication.

FIG. 8 is a conceptual data flow diagram illustrating the data flowbetween different modules/means/components in an example apparatus.

FIG. 9 is a diagram illustrating an example of a hardware implementationfor an apparatus employing a processing system.

FIG. 10 is a flow chart of a method of wireless communication.

FIG. 11 is a conceptual data flow diagram illustrating the data flowbetween different modules/means/components in an example apparatus.

FIG. 12 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purposes of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well-known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented withreference to various apparatus and methods. These apparatus and methodswill be described in the following detailed description and illustratedin the accompanying drawings by various blocks, modules, components,circuits, steps, processes, algorithms, and/or the like (collectivelyreferred to as “elements”). These elements may be implemented usingelectronic hardware, computer software, or any combination thereof.Whether such elements are implemented as hardware or software dependsupon the particular application and design constraints imposed on theoverall system.

By way of example, an element, or any portion of an element, or anycombination of elements may be implemented with a “processing system”that includes one or more processors. Examples of processors includemicroprocessors, microcontrollers, digital signal processors (DSPs),field programmable gate arrays (FPGAs), programmable logic devices(PLDs), state machines, gated logic, discrete hardware circuits, andother suitable hardware configured to perform the various functionalitydescribed throughout this disclosure. One or more processors in theprocessing system may execute software. Software shall be construedbroadly to mean instructions, instruction sets, code, code segments,program code, programs, subprograms, software modules, applications,software applications, software packages, routines, subroutines,objects, executables, threads of execution, procedures, functions,and/or the like, whether referred to as software, firmware, middleware,microcode, hardware description language, or otherwise.

Accordingly, in one or more example embodiments, the functions describedmay be implemented in hardware, software, firmware, or any combinationthereof. If implemented in software, the functions may be stored on orencoded as one or more instructions or code on a computer-readablemedium. Computer-readable media includes computer storage media. Storagemedia may be any available media that can be accessed by a computer. Byway of example, and not limitation, such computer-readable media cancomprise a random-access memory (RAM), a read-only memory (ROM), anelectrically erasable programmable ROM (EEPROM), compact disk ROM(CD-ROM) or other optical disk storage, magnetic disk storage or othermagnetic storage devices, combinations of the aforementioned types ofcomputer-readable media, or any other medium that can be used to storecomputer executable code in the form of instructions or data structuresthat can be accessed by a computer.

An access point (AP) may comprise, be implemented as, or known as aNodeB, a Radio Network Controller (RNC), an eNodeB (eNB), a Base StationController (BSC), a Base Transceiver Station (BTS), a Base Station (BS),a Transceiver Function (TF), a Radio Router, a Radio Transceiver, aBasic Service Set (BSS), an Extended Service Set (ESS), a Radio BaseStation (RBS), a Node B (NB), a gNB, a 3G NB, a NR BS, a TransmitReceive Point (TRP), or some other terminology.

An access terminal (AT) may comprise, be implemented as, or be known asan access terminal, a subscriber station, a subscriber unit, a mobilestation, a remote station, a remote terminal, a user terminal, a useragent, a user device, user equipment (UE), a user station, a wirelessnode, or some other terminology. In some aspects, an access terminal maycomprise a cellular telephone, a smart phone, a cordless telephone, aSession Initiation Protocol (SIP) phone, a wireless local loop (WLL)station, a personal digital assistant (PDA), a tablet, a netbook, asmartbook, an ultrabook, a handheld device having wireless connectioncapability, a Station (STA), or some other suitable processing deviceconnected to a wireless modem. Accordingly, one or more aspects taughtherein may be incorporated into a phone (e.g., a cellular phone, a smartphone), a computer (e.g., a desktop), a portable communication device, aportable computing device (e.g., a laptop, a personal data assistant, atablet, a netbook, a smartbook, an ultrabook), wearable device (e.g.,smart watch, smart glasses, smart bracelet, smart wristband, smart ring,smart clothing, and/or the like), medical devices or equipment,biometric sensors/devices, an entertainment device (e.g., music device,video device, satellite radio, gaming device, and/or the like), avehicular component or sensor, smart meters/sensors, industrialmanufacturing equipment, a global positioning system device, or anyother suitable device that is configured to communicate via a wirelessor wired medium. In some aspects, the node is a wireless node. Awireless node may provide, for example, connectivity for or to a network(e.g., a wide area network such as the Internet or a cellular network)via a wired or wireless communication link.

Some UEs may be considered machine-type communication (MTC) UEs, whichmay include remote devices that may communicate with a base station,another remote device, or some other entity. Machine type communications(MTC) may refer to communication involving at least one remote device onat least one end of the communication and may include forms of datacommunication which involve one or more entities that do not necessarilyneed human interaction. MTC UEs may include UEs that are capable of MTCcommunications with MTC servers and/or other MTC devices through PublicLand Mobile Networks (PLMN), for example. Examples of MTC devicesinclude sensors, meters, location tags, monitors, drones, robots/roboticdevices, and/or the like. In some aspects, MTC devices may be referredto as enhanced MTC (eMTC) devices, LTE category M1 (LTE-M) devices,machine to machine (M2M) devices, and/or the like. Additionally, oralternatively, some UEs may be narrowband Internet of things (NB-IoT)devices.

It is noted that while aspects may be described herein using terminologycommonly associated with 3G and/or 4G wireless technologies, aspects ofthe present disclosure can be applied in other generation-basedcommunication systems, such as 3G and later, including NR technologies.

FIG. 1 is a diagram illustrating a network 100 in which aspects of thepresent disclosure may be practiced. The network 100 may be an LTEnetwork or some other wireless network, such as a 3G or NR network.Wireless network 100 may include a number of BSs 110 (shown as BS 110 a,BS 110 b, BS 110 c, and BS 110 d) and other network entities. A BS is anentity that communicates with user equipment (UEs) and may also bereferred to as a base station, a NR BS, a Node B, a gNB, a 3G NB, anaccess point, a TRP, and/or the like. Each BS may provide communicationcoverage for a particular geographic area. In 3GPP, the term “cell” canrefer to a coverage area of a BS and/or a BS subsystem serving thiscoverage area, depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or another type of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a closed subscriber group (CSG)). A BS for a macro cell may bereferred to as a macro BS. A BS for a pico cell may be referred to as apico BS. A BS for a femto cell may be referred to as a femto BS or ahome BS. In the example shown in FIG. 1 , a BS 110 a may be a macro BSfor a macro cell 102 a, a BS 110 b may be a pico BS for a pico cell 102b, and a BS 110 c may be a femto BS for a femto cell 102 c. ABS maysupport one or multiple (e.g., three) cells. The terms “eNB”, “basestation”, “NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” maybe used interchangeably herein.

In some examples, a cell may not necessarily be stationary, and thegeographic area of the cell may move according to the location of amobile BS. In some examples, the BSs may be interconnected to oneanother and/or to one or more other BSs or network nodes (not shown) inthe access network 100 through various types of backhaul interfaces suchas a direct physical connection, a virtual network, and/or the likeusing any suitable transport network.

Wireless network 100 may also include relay stations. A relay station isan entity that can receive a transmission of data from an upstreamstation (e.g., a BS or a UE) and send a transmission of the data to adownstream station (e.g., a UE or a BS). A relay station may also be aUE that can relay transmissions for other UEs. In the example shown inFIG. 1 , a relay station 110 d may communicate with macro BS 110 a and aUE 120 d in order to facilitate communication between BS 110 a and UE120 d. A relay station may also be referred to as a relay BS, a relaybase station, a relay, and/or the like.

Wireless network 100 may be a heterogeneous network that includes BSs ofdifferent types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/orthe like. These different types of BSs may have different transmit powerlevels, different coverage areas, and different impact on interferencein wireless network 100. For example, macro BSs may have a high transmitpower level (e.g., 3 to 40 Watts) whereas pico BSs, femto BSs, and relayBSs may have lower transmit power levels (e.g., 0.1 to 2 Watts).

A network controller 130 may couple to a set of BSs and may providecoordination and control for these BSs. Network controller 130 maycommunicate with the BSs via a backhaul. The BSs may also communicatewith one another, e.g., directly or indirectly via a wireless orwireline backhaul.

UEs 120 (e.g., 120 a, 120 b, 120 c) may be dispersed throughout wirelessnetwork 100, and each UE may be stationary or mobile. A UE may also bereferred to as an access terminal, a terminal, a mobile station, asubscriber unit, a station, and/or the like. A UE may be a cellularphone (e.g., a smart phone), a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, alaptop computer, a cordless phone, a wireless local loop (WLL) station,a tablet, a camera, a gaming device, a netbook, a smartbook, anultrabook, medical device or equipment, biometric sensors/devices,wearable devices (smart watches, smart clothing, smart glasses, smartwrist bands, smart jewelry (e.g., smart ring, smart bracelet)), anentertainment device (e.g., a music or video device, or a satelliteradio), a vehicular component or sensor, smart meters/sensors,industrial manufacturing equipment, a global positioning system device,or any other suitable device that is configured to communicate via awireless or wired medium. Some UEs may be considered evolved or enhancedmachine-type communication (eMTC) UEs. MTC and eMTC UEs include, forexample, robots, drones, remote devices, such as sensors, meters,monitors, location tags, and/or the like, that may communicate with abase station, another device (e.g., remote device), or some otherentity. A wireless node may provide, for example, connectivity for or toa network (e.g., a wide area network such as Internet or a cellularnetwork) via a wired or wireless communication link. Some UEs may beconsidered Internet-of-Things (IoT) devices. Some UEs may be considereda Customer Premises Equipment (CPE).

In FIG. 1 , a solid line with double arrows indicates desiredtransmissions between a UE and a serving BS, which is a BS designated toserve the UE on the downlink and/or uplink. A dashed line with doublearrows indicates potentially interfering transmissions between a UE anda BS.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular RAT andmay operate on one or more frequencies. A RAT may also be referred to asa radio technology, an air interface, and/or the like. A frequency mayalso be referred to as a carrier, a frequency channel, and/or the like.Each frequency may support a single RAT in a given geographic area inorder to avoid interference between wireless networks of different RATs.In some cases, NR or 3G RAT networks may be deployed. In such a case, NRor 3G RATs may use single-carrier waveforms (e.g., SC-FDM) and/or in ammWave band.

In some examples, access to the air interface may be scheduled, whereina scheduling entity (e.g., a base station) allocates resources forcommunication among some or all devices and equipment within thescheduling entity's service area or cell (e.g., using a PDCCH). Forexample, the scheduling entity may identify a device or equipment,within the scheduling entity's service area or cell, to receive ascheduling grant, may generate a control channel to provide thescheduling grant, wherein the scheduling grant is encoded into arelevant sample associated with a particular aggregation level of aplurality of aggregation levels, and may provide the control channelincluding the relevant sample.

Within the present disclosure, as discussed further below, thescheduling entity may be responsible for scheduling, assigning,reconfiguring, and releasing resources for one or more subordinateentities. That is, for scheduled communication, subordinate entitiesutilize resources allocated by the scheduling entity.

Base stations are not the only entities that may function as ascheduling entity. That is, in some examples, a UE may function as ascheduling entity, scheduling resources for one or more subordinateentities (e.g., one or more other UEs). In this example, the UE isfunctioning as a scheduling entity, and other UEs utilize resourcesscheduled by the UE for wireless communication. A UE may function as ascheduling entity in a peer-to-peer (P2P) network, and/or in a meshnetwork. In a mesh network example, UEs may optionally communicatedirectly with one another in addition to communicating with thescheduling entity.

Thus, in a wireless communication network with a scheduled access totime-frequency resources and having a cellular configuration, a P2Pconfiguration, and a mesh configuration, a scheduling entity and one ormore subordinate entities may communicate utilizing the scheduledresources.

As indicated above, FIG. 1 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 1 .

FIG. 2 shows a block diagram 200 of a design of BS 110 and UE 120, whichmay be one of the base stations and one of the UEs in FIG. 1 . BS 110may be equipped with T antennas 234 a through 234 t, and UE 120 may beequipped with R antennas 252 a through 252 r, where in general T≥1 andR≥1.

At BS 110, a transmit processor 220 may receive data from a data source212 for one or more UEs, select one or more modulation and codingschemes (MCS) for each UE based at least in part on channel qualityindicators (CQIs) received from the UE, process (e.g., encode andmodulate) the data for each UE based at least in part on the MCS(s)selected for the UE, and provide data symbols for all UEs. Transmitprocessor 220 may also process system information (e.g., for semi-staticresource partitioning information (SRPI), and/or the like) and controlinformation (e.g., CQI requests, grants, upper layer signaling, and/orthe like) and provide overhead symbols and control symbols. Transmitprocessor 220 may also generate reference symbols for reference signals(e.g., the CRS) and synchronization signals (e.g., the primarysynchronization signal (PSS) and secondary synchronization signal(SSS)). A transmit (TX) multiple-input multiple-output (MIMO) processor230 may perform spatial processing (e.g., precoding) on the datasymbols, the control symbols, the overhead symbols, and/or the referencesymbols, if applicable, and may provide T output symbol streams to Tmodulators (MODs) 232 a through 232 t. Each modulator 232 may process arespective output symbol stream (e.g., for OFDM and/or the like) toobtain an output sample stream. Each modulator 232 may further process(e.g., convert to analog, amplify, filter, and upconvert) the outputsample stream to obtain a downlink signal. T downlink signals frommodulators 232 a through 232 t may be transmitted via T antennas 234 athrough 234 t, respectively. In some aspects, the transmit processor 220and/or modulator 232 may communicate according to DFT-s-OFDM. In such acase, the transmit processor 220 and/or modulator 232 may add a DFTspreading step before tone mapping of the frequency domain samples tooutput samples.

At UE 120, antennas 252 a through 252 r may receive the downlink signalsfrom BS 110 and/or other base stations and may provide received signalsto demodulators (DEMODs) 254 a through 254 r, respectively. Eachdemodulator 254 may condition (e.g., filter, amplify, downconvert, anddigitize) a received signal to obtain input samples. Each demodulator254 may further process the input samples (e.g., for OFDM and/or thelike) to obtain received symbols. A MIMO detector 256 may obtainreceived symbols from all R demodulators 254 a through 254 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. A receive (RX) processor 258 may process (e.g.,demodulate and decode) the detected symbols, provide decoded data for UE120 to a data sink 260, and provide decoded control information andsystem information to a controller/processor 280. A channel processormay determine reference signal received power (RSRP), received signalstrength indicator (RSSI), reference signal received quality (RSRQ),channel quality indicator (CQI), and/or the like.

On the uplink, at UE 120, a transmit processor 264 may receive andprocess data from a data source 262 and control information (e.g., forreports comprising RSRP, RSSI, RSRQ, CQI, and/or the like) fromcontroller/processor 280. Transmit processor 264 may also generatereference symbols for one or more reference signals. The symbols fromtransmit processor 264 may be precoded by a TX MIMO processor 266 ifapplicable, further processed by modulators 254 a through 254 r (e.g.,for DFT-s-OFDM, CP-OFDM, and/or the like), and transmitted to BS 110. AtBS 110, the uplink signals from UE 120 and other UEs may be received byantennas 234, processed by demodulators 232, detected by a MIMO detector236 if applicable, and further processed by a receive processor 238 toobtain decoded data and control information sent by UE 120. Receiveprocessor 238 may provide the decoded data to a data sink 239 and thedecoded control information to controller/processor 240. BS 110 mayinclude communication unit 244 and communicate to network controller 130via communication unit 244. Network controller 130 may includecommunication unit 294, controller/processor 290, and memory 292.

Controllers/processors 240 and 280 and/or any other component(s) in FIG.2 may direct the operation at BS 110 and UE 120, respectively, toperform downlink control channel design using a top-to-bottom searchspace. For example, controller/processor 280 and/or other processors andmodules at BS 110, may perform or direct operations of UE 120 to performdownlink control channel design using a top-to-bottom search space. Forexample, controller/processor 280 and/or other controllers/processorsand modules at BS 110 may perform or direct operations of, for example,method 900 of FIG. 9 , method 1200 of FIG. 12 , and/or other processesas described herein. In some aspects, one or more of the componentsshown in FIG. 2 may be employed to perform example method 900 of FIG. 9, method 1200 of FIG. 12 , and/or other processes for the techniquesdescribed herein. Memories 242 and 282 may store data and program codesfor BS 110 and UE 120, respectively. A scheduler 246 may schedule UEsfor data transmission on the downlink and/or uplink.

As indicated above, FIG. 2 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 2 .

FIG. 3 illustrates an example logical architecture of a distributed RAN300, according to aspects of the present disclosure. A 5G access node306 may include an access node controller (ANC) 302. The ANC may be acentral unit (CU) of the distributed RAN 300. The backhaul interface tothe next generation core network (NG-CN) 304 may terminate at the ANC.The backhaul interface to neighboring next generation access nodes(NG-ANs) may terminate at the ANC. The ANC may include one or more TRPs308 (which may also be referred to as BSs, NR BSs, Node Bs, 5G NBs, APs,gNB, or some other term). As described above, a TRP may be usedinterchangeably with “cell.”

The TRPs 308 may be a distributed unit (DU). The TRPs may be connectedto one ANC (ANC 302) or more than one ANC (not illustrated). Forexample, for RAN sharing, radio as a service (RaaS), and servicespecific AND deployments, the TRP may be connected to more than one ANC.A TRP may include one or more antenna ports. The TRPs may be configuredto individually (e.g., dynamic selection) or jointly (e.g., jointtransmission) serve traffic to a UE.

The local architecture of RAN 300 may be used to illustrate fronthauldefinition. The architecture may be defined that support fronthaulingsolutions across different deployment types. For example, thearchitecture may be based at least in part on transmit networkcapabilities (e.g., bandwidth, latency, and/or jitter).

The architecture may share features and/or components with LTE.According to aspects, the next generation AN (NG-AN) 310 may supportdual connectivity with NR. The NG-AN may share a common fronthaul forLTE and NR.

The architecture may enable cooperation between and among TRPs 308. Forexample, cooperation may be preset within a TRP and/or across TRPs viathe ANC 302. According to aspects, no inter-TRP interface may beneeded/present.

According to aspects, a dynamic configuration of split logical functionsmay be present within the architecture of RAN 300. The packet dataconvergence protocol (PDCP), radio link control (RLC), media accesscontrol (MAC) protocol may be adaptably placed at the ANC or TRP.

According to certain aspects, a BS may include a central unit (CU)(e.g., ANC 302) and/or one or more distributed units (e.g., one or moreTRPs 308).

As indicated above, FIG. 3 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 3 .

FIG. 4 illustrates an example physical architecture of a distributed RAN400, according to aspects of the present disclosure. A centralized corenetwork unit (C-CU) 402 may host core network functions. The C-CU may becentrally deployed. C-CU functionality may be offloaded (e.g., toadvanced wireless services (AWS)), in an effort to handle peak capacity.

A centralized RAN unit (C-RU) 404 may host one or more ANC functions.Optionally, the C-RU may host core network functions locally. The C-RUmay have distributed deployment. The C-RU may be closer to the networkedge.

A distributed unit (DU) 406 may host one or more TRPs. The DU may belocated at edges of the network with radio frequency (RF) functionality.

As indicated above, FIG. 4 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 4 .

A BS may convey control information to a UE on a control channel. Forexample, the control channel may include a physical downlink controlchannel (PDCCH) and/or the like. The PDCCH may include a plurality ofresource elements (REs) that are grouped into resource element groups(REGs). A plurality of REGs may collectively be referred to as a controlchannel element (CCE). One or more CCEs may be allocated for a UE, andcontrol information for the UE may be encoded on the one or more CCEs.The group of one or more CCEs allocated to the UE may be referred to asa coreset of the UE.

As one example, the control information may be provided on a single CCEwhen the control information can be provided using a single CCE, andadditional CCEs may be allocated to the UE when the control informationexceeds the size of a single CCE. A single CCE, and a set of CCEs, maybe associated with respective aggregation levels. For example, thesingle CCE may have a lowest aggregation level, and in some aspects, aREG may contain 12 contiguous REs (e.g., twelve frequency tones of asingle symbol), and a CCE may contain a fixed quantity of REGs. The REGsand/or the CCEs may be distributed or localized in time (e.g., over OFDMsymbols) and/or frequency (e.g., over multiple resource blocks (RBs)).

In some cases, a BS may provide control information for multiple,different UEs on the PDCCH. For example, the BS may provide a cell thatcovers a group of UEs, and may provide respective coresets for each UE,of the group of UEs, on the PDCCH. In such a case, each coreset may beencoded using a respective seed (e.g., a random seed) corresponding toeach UE. A UE may then search the PDCCH for a coreset that correspondsto the UE, and may decode the corresponding coreset based at least inpart on the respective seed. A UE may search within a respective searchspace for a candidate sample including the corresponding coreset. Forexample, in a legacy network, such as LTE, the PDCCH may be arranged ina particular fashion, with a common region that all UEs monitor and oneor more UE-specific regions that are monitored by corresponding UEs. AUE may perform a blind search within the common region and a UE-specificregion corresponding to the UE. For example, the UE may attempt todecode candidate samples at a first, lower aggregation level (e.g.,associated with one CCE per coreset), until the UE finds a candidatesample that can be successfully decoded by the UE to obtain a coresetfor the UE. If the UE cannot find a decodable candidate sample at thelower aggregation level, the UE may proceed to a second, higheraggregation level (e.g., associated with two CCEs per coreset), and maycontinue the search.

The above approach may be referred to as a bottom-to-top searchtechnique. The bottom-to-top search technique may work well in LTEnetworks, in which the BS encodes the PDCCH based on the bottom-to-topapproach, but may pose certain problems in 3G/NR networks, especially ina millimeter wave (mmWave) deployment, with the use of time-domain-basedwaveforms such as DFT-S-OFDM. For example, gaps between candidatesamples or coresets may occur when using such a bottom-to-top searchtechnique (e.g., when no control information is to be encoded on aparticular symbol, the particular symbol may be a gap between encodedsymbols). This may degrade the single-carrier properties of the 3G/NRcarrier signal due to the higher peak to average power ratio (PAPR) thatoccurs due to the gaps. Furthermore, in mmWave deployments, a BS may belikely to simultaneously transmit to a smaller quantity of UEs than in alegacy network, so the bottom-to-top search technique may be inefficientin such situations, in addition to causing detriment to thesingle-carrier properties of the 3G/NR carrier signal.

Techniques and apparatuses, described herein, provide generation of aPDCCH to minimize gaps in the PDCCH, and provide searching of the PDCCHbased at least in part on a top-to-bottom search space. For example,when a BS transmits to a single UE, the BS may transmit PDCCH on acandidate sample in the coreset for the UE that occupies an entirety ofthe coreset (e.g., at a highest aggregation level). The UE may performthe blind search in a top-to-bottom fashion (e.g., searching for acandidate sample on the highest aggregation level spanning the entiretyof the coreset, then searching for candidate samples on subsets of thecoreset at lower aggregation levels). Thus, the BS avoids degradation ofthe single-carrier waveform due to gaps between candidate samples whenserving a single UE. This may be particularly useful for mmWave, sincemmWave BSs are more likely to transmit to a single UE at a given timethan other types of BSs. Furthermore, techniques and apparatusesdescribed herein enable generation of a PDCCH to minimize gaps in thePDCCH for control information for multiple UEs using the top-to-bottomsearch space, which improves efficiency and reduces degradation of thesingle-carrier waveform for the multiple UEs.

FIG. 5 is a diagram illustrating an example 500 of a top-to-bottomsearch space for control resource sets in New Radio. For example, FIG. 5shows an example of how a PDCCH payload region 502 can be divided intocandidate samples of various aggregation levels (ALs). For example, thePDCCH payload region may include an OFDM symbol of a control region of asubframe, and REs, REGs, and CCEs of the OFDM symbol may be mapped toone or more UEs 120 that are to receive downlink control information(DCI) as part of the PDCCH payload region 502. In aspects describedherein, a BS may select ALs for control signals so that gaps in thePDCCH payload region are minimized or reduced as compared to in LTEand/or using a bottom-to-top approach. For a description of how a UEmight scan or perform a search of the search space, refer to FIGS.6A-6D, below.

As shown by reference number 504, in some aspects, the candidate samplesat different ALs may be determined based at least in part on localizedsplitting. For example, and as shown, a candidate sample associated withAL1 may span an entirety of the coreset or PDCCH payload region 502, andcandidate samples associated with AL1/2 (e.g., a lower AL than AL1) mayeach span half of the coreset or PDCCH payload region 502. As furthershown, pairs of candidate samples associated with AL1/4 (e.g., a lowerAL than AL1/2) may be formed from portions of the PDCCH payload region502 associated with the candidate samples associated with AL1/2.Localized splitting may be simpler to implement than distributedsplitting, but may reduce time diversity of the candidate samples. Whilethe ALs shown in the localized splitting aspect of FIG. 5 are shown withAL1/8 at the top, a UE 120 that is performing a blind search of thePDCCH payload region may begin at AL1, and may move to decreasing ALlevels if decoding of the candidate sample at AL1 is unsuccessful. Inother words, the top-to-bottom direction shown in FIG. 5 is not intendedto indicate a search space direction of the UE 120.

As shown by reference number 506, in some aspects, the candidate samplesat different ALs may be determined based at least in part on distributedsplitting. For example, and as shown, each candidate sample at AL1/2 maycorrespond to two non-adjacent candidate samples at AL1/4. As furthershown, each candidate sample at AL1/4 may correspond to two non-adjacentcandidate samples at AL 1/8. The distributed splitting approach mayprovide increased time diversity of the DCI as compared to the localizedsplitting approach.

While the candidate samples in FIG. 5 are shown with an n{circumflexover ( )}2 splitting ratio and ALs of 1, 1/2, 1/4, and 1/8, a differentsplitting ratio may be used. For example, a n{circumflex over ( )}3splitting ratio (with ALs of 1, 1/3, 1/9, 1/27, and so on), or any othersplitting ratio may be used.

In some aspects, the candidate samples may have different quantities ofresource elements. For example, based at least in part on a quantity ofresources in a coreset, a uniform split (e.g., a two-way split, athree-way split, and/or the like) may not be possible. In such a case,some rounding may be needed. For example, a candidate sample having 45resource elements may be divided, at a lower aggregation level, into twocandidate samples having 23 resource elements and 22 resource elements.

As indicated above, FIG. 5 is provided as an example. Other examples arepossible and may differ from what was described with respect to FIG. 5 .

FIGS. 6A-6D are diagrams illustrating examples 600 of providing downlinkcontrol information to one or more UEs using a top-to-bottom searchspace.

As shown in FIG. 6A, and by reference number 602, a BS 110 maycommunicate with a UE 120 via a mmWave link. For example, the BS 110 maytransmit downlink traffic to the UE 120 and/or receive uplink trafficfrom the UE 120 on the mmWave link. Aspects of the present disclosuremay be particularly useful for mmWave communication between BS 110 andUE 120 because BS 110 may cover fewer UEs 120 when using mmWave thanwhen using other radio access technologies. For example, due to thebeamformed signal and/or decreased coverage range of mmWave, the BS 110may cover one UE 120, two UEs 120, three UEs 120, and/or the like. This,in turn, may allow the BS 110 to use an entirety of the PDCCH controlregion for a single UE 120, or to reduce a quantity of different UEs 120for which control signaling is provided, thereby preserving thesingle-carrier properties of the mmWave signal.

As shown by reference number 604, the BS 110 may determine to scheduletraffic for the covered UE (e.g., UE 120) to minimize gaps in the PDCCHpayload region. For example, the BS 110 may provide DCI on a PDCCHpayload region (e.g., or a PDCCH control region). The BS 110 may selecta particular aggregation level for the DCI to minimize the gaps, asdescribed below.

As shown by reference number 606, to minimize gaps in the PDCCH payloadregion, the BS 110 may provide the DCI to the UE 120 on an AL1 candidatesample. For example, the AL1 candidate sample may span an entirety ofthe PDCCH payload region. The BS 110 may provide the DCI on the AL1candidate sample since UE 120 is the only UE covered by the BS 110, andsince providing the DCI on the AL1 candidate sample will occupy theentire PDCCH payload region, thereby eliminating gaps. In this way, theBS 110 reduces gaps, and, therefore, PAPR of the downlink signal, whichpreserves the single-carrier properties of the downlink signal, therebysimplifying amplification and improving throughput in the network.

As shown by reference number 608, the UE 120 may scan the PDCCH payloadregion to identify the DCI (or a relevant sample). For example, the UE120 may perform a blind search of the PDCCH payload region, starting ata highest aggregation level (e.g., AL1), to identify a relevant samplethat includes the DCI.

In some aspects, the UE 120 may start scanning or searching at a loweraggregation level than the highest aggregation level. For example, whenthe UE 120 is to receive multiple, different DCIs corresponding tomultiple, different control signals, the UE 120 may start scanning atAL1/2 or a lower AL (as described in connection with FIGS. 6B and 6D,below. Additionally, or alternatively, it is possible that the UE 120may not need all resources of the PDCCH payload region. In such a case,a search space of the UE 120 can begin at a lower aggregation level(e.g., AL1/4, if AL1/4 contains sufficient resources for the DCI), whichis configured by the base station. In such a case, in some aspects, theBS 110 may frontload the DCI in the PDCCH payload region, and may leavea remainder of the PDCCH payload region empty, may fill the remainder ofthe PDCCH payload region with padding bits, or may use the remainder ofthe PDCCH as a downlink shared channel, or to transmit PDCCH to anotherUE.

As shown by reference number 610, the UE 120 may identify the A1candidate sample based at least in part on scanning the PDCCH payloadregion. For example, the UE 120 may attempt to decode a prefix of the A1candidate sample based at least in part on a seed associated with the UE120, and may successfully decode the prefix. Thus, the UE 120 maydetermine that the A1 candidate sample is associated with the UE 120.

As shown by reference number 612, the UE 120 may decode the AL1candidate sample to obtain the DCI associated with UE 120. In this way,the BS 110 provides DCI using a candidate sample that spans an entiretyof the PDCCH payload region, which reduces PAPR of the downlink signaland improves amplifier accuracy. Further, the UE 120 begins searching orscanning at the highest aggregation level (e.g., the aggregation levelof the candidate sample that spans the entirety of the PDCCH payloadregion) which conserves resources of the UE 120 that would otherwise beused to start searching or scanning at a lower aggregation level (e.g.,using a bottom-to-top approach).

As shown in FIG. 6B, and by reference number 614, the BS 110 maydetermine to schedule traffic for UE 120 with two grants to minimizegaps in the PDCCH payload region. To schedule the traffic, the BS 110may provide a first DCI and a second DCI to the UE 120. In such a case,the BS 110 may select a lower AL than the highest AL (e.g., AL1). Forexample, and as shown, the BS 110 may use a respective AL1/2 coreset foreach of the first DCI and the second DCI. BS 110 may use the AL1/2coreset so that an entirety of the PDCCH payload region is occupied bythe first DCI and the second DCI, thereby reducing gaps in the PDCCHpayload region.

As shown by reference number 616, the UE 120 may scan the PDCCH payloadregion to identify the first DCI and the second DCI. In some aspects,the UE 120 may start by scanning or searching at a highest aggregationlevel (e.g., AL1), and may proceed to scan at AL1/2 when decoding of thecandidate sample at AL1 is unsuccessful. Additionally, or alternatively,the UE 120 may be configured to start scanning at AL1/2 (e.g., based atleast in part on RRC signaling between the BS 110 and the UE 120), andmay identify a first candidate sample and a second candidate sample atAL1/2. In this way, the PDCCH payload region may include multiplecoresets of a highest AL that a UE 120 is configured to search. This maypermit the BS 110 to handle multiple grants with regard to a single UE120. In such a case, it is possible that there may be no other UE 120 toshare the PDCCH payload region with the UE 120 and, in such a case, thePDCCH payload region may not be fully occupied. This may lead todegradation of PAPR. However, such a degradation may be balanced againstthe benefit to be gained by providing first and second DCI as part of asingle PDCCH payload region.

In some aspects, the BS 110 may provide a DCI at a lower AL based atleast in part on a location of a UE 120 relative to the BS 110. Forexample, when a signal path to the UE 120 is longer, the BS 110 mayprovide the DCI at a higher AL, and when the signal path to the UE 120is shorter, the BS 110 may provide the DCI at a lower AL. By providingthe DCI at a higher AL, the BS 110 may provide additional redundancy ormay use a lower modulation and coding scheme, which may improvelikelihood of successful decoding by the UE 120. By providing the DCI ata lower AL, the BS 110 may reduce an amount of resources required toprovide the DCI.

As shown by reference number 618, and as described in more detail inconnection with FIG. 6A, above, the UE 120 may identify relevant samplesincluding the first DCI and the second DCI based at least in part onscanning the PDCCH payload region. As shown by reference number 620, andas also described in more detail in connection with FIG. 6A, the UE 120may decode the relevant samples to obtain the first DCI and the secondDCI. Thus, the UE 120 obtains two DCIs using a top-to-bottom searchspace, which reduces PAPR of the downlink signal and conserves resourcesof the UE 120 that would otherwise be used to perform a bottom-to-topsearch of the PDCCH payload region.

As shown in FIG. 6C, and by reference number 622, in some aspects, theBS 110 may cover two UEs (e.g., UEs 120-1 and 120-2). In such a case,and as shown by reference number 624, the BS 110 may determine toschedule downlink traffic for the UEs 120-1 and 120-2 with one grant foreach UE 120 to minimize gaps in the PDCCH payload region.

As shown by reference number 626, the BS 110 may provide a DCI for UE120-1 on a first portion of the PDCCH payload region, and may provide aDCI for UE 120-2 on a second portion of the PDCCH payload region. Thus,the BS 110 may provide DCIs for two UEs 120 on a single PDCCH payloadregion using a highest possible aggregation level, which may reduce gapsand PAPR of the downlink signal and improve single-carrier performanceof the system. In such a case, hashing may be used to reduce blockingbetween the UE 120-1 and 120-2 when grants for the UE 120-1 and 120-2are included in a single coreset or PDCCH payload region. For example,the grants (e.g., DCIs, etc.) may be encoded based at least in part on arespective seed associated with the UEs 120-1 and 120-2.

As shown by reference number 628, the respective UEs 120 may scan thePDCCH payload region, may identify the respective relevant samples atthe AL1/2 aggregation level, and may decode the respective relevantsamples to obtain the respective DCIs. In some aspects, the respectiveUEs 120 may each scan a candidate sample at the AL1 aggregation level,then may scan candidate samples at the AL1/2 aggregation level toidentify relevant samples. Additionally, or alternatively, therespective UEs 120 may be configured to first scan at the AL1/2 level(e.g., based at least in part on RRC signaling between the BS 110 andthe respective UEs 120). The respective UEs 120 may decode the relevantsamples to obtain the respective DCIs.

FIG. 6D shows an example of providing DCIs for two grants to a UE 120-1and a single DCI for a grant to a UE 120-2. As shown in FIG. 6D, and byreference number 630, the BS 110 may determine to schedule traffic forthe UEs 120-1 and 120-2 to minimize gaps in the PDCCH payload region(e.g., for the two grants associated with the UE 120-1 and the singlegrant associated with UE 120-2).

As shown by reference number 632, the BS 110 may provide the PDCCHpayload region to the UEs 120-1 and 120-2. As further shown, the PDCCHpayload region may include first and second portions corresponding tothe UE 120-1, and a third portion corresponding to the UE 120-2. Asshown, the first and second portions may be associated with anaggregation level of AL1/4, and the third portion may be associated withan aggregation level of AL1/2. In this way, the BS 110 may provide twogrants to one UE 120, and a single grant to another UE 120, using asingle PDCCH payload region. Further, the BS 110 may select highestpossible ALs for the respective DCIs, which reduces or eliminates gapsin the PDCCH payload region, even when multiple UEs 120 are associatedwith the PDCCH payload region.

As shown by reference number 634, the UEs 120-1 and 120-2 may scan thePDCCH payload region, may identify the respective relevant samples atthe AL1/2 level and the AL1/4 level, and may decode the respectiverelevant samples to obtain the respective DCI for the UEs 120-1 and120-2. In some aspects, the UEs 120-1 and 120-2 may start scanning atthe AL1 aggregation level, and may proceed to scan at lower aggregationlevels until the respective relevant samples are identified.Additionally, or alternatively, the UEs 120-1 and 120-2 may startscanning at the AL1/2 and/or the AL1/4 aggregation level (e.g., based atleast in part on configuration of the UEs 120-1 and 120-2) which mayconserve resources that would be used to start scanning at the highestpossible aggregation level.

As indicated above, FIGS. 6A-6D are provided as examples. Other examplesare possible and may differ from what was described with respect toFIGS. 6A-6D.

FIG. 7 is a flow chart of a method 700 of wireless communication. Themethod may be performed by a UE (e.g., the UE 120 of FIG. 1 , theapparatus 802/802′, and/or the like).

At 710, the UE may receive a control channel that includes a pluralityof candidate samples having at least two aggregation levels. Forexample, the UE 120 may receive a control channel, such as a PDCCH. Thecontrol channel may include a plurality of candidate samples, such as aplurality of regions of different sizes that may include DCI relevant tothe UE. The plurality of regions may have at least two aggregationlevels, such as a highest aggregation level spanning an entirety of thecontrol channel and one or more other aggregation levels that aresubsets of the control channel.

At 720, the UE may scan a set of candidate samples, of the plurality ofcandidate samples, to identify a relevant sample. In some aspects, thescanning is performed on the set of candidate samples in an order from ahigher aggregation level of the at least two aggregation levels to alower aggregation level of the at least two aggregation levels. Forexample, the UE may scan a set of candidate samples using atop-to-bottom scanning approach. In some aspects, the UE may scan theset of candidate samples starting at the highest aggregation level. Insome aspects, the UE may start at a lower aggregation level (i.e., lowerthan the highest aggregation level).

At 730, the UE may scan for two or more relevant samples. For example,in such a case, each relevant sample, of the two or more relevantsamples, may be associated with a respective grant.

At 740, the UE may decode the relevant sample. For example, the UE maydecode the relevant sample based at least in part on a hash or seedassociated with the UE.

Method 700 may include additional aspects, such as any single aspect orany combination of aspects described below.

In some aspects, a candidate sample associated with a highestaggregation level includes an entirety of the control channel. In someaspects, a candidate sample of the higher aggregation level includesmultiple, different candidate samples of the lower aggregation level. Insome aspects, at least two candidate samples of a particular aggregationlevel include different quantities of resource elements. In someaspects, the control channel is associated with a plurality ofaggregation levels including the at least two aggregation levels, andthe at least two aggregation levels do not include a highest aggregationlevel of the plurality of aggregation levels. In some aspects, the UE isconfigured to scan for two or more relevant samples, wherein eachrelevant sample, of the two or more relevant samples, is associated witha respective grant. In some aspects, the UE is a first UE, and thecontrol channel includes a candidate sample that is relevant to a secondUE. In some aspects, the candidate sample that is relevant to the secondUE has a different aggregation level than the relevant sample. In someaspects, the control channel further includes hashing information toreduce blocking between the first UE and the second UE.

Although FIG. 7 shows example blocks of a method of wirelesscommunication, in some aspects, the method may include additionalblocks, fewer blocks, different blocks, or differently arranged blocksthan those shown in FIG. 7 . Additionally, or alternatively, two or moreblocks shown in FIG. 7 may be performed in parallel.

FIG. 8 is a conceptual data flow diagram 800 illustrating the data flowbetween different modules/means/components in an example apparatus 802.The apparatus 802 may be a UE (e.g., the UE 120 of FIG. 1 ). In someaspects, the apparatus 802 includes a reception module 804, a scanningmodule 806, a decoding module 808, and/or a transmission module 810.

The reception module 804 may receive data 812 from a base station 850(e.g., the BS 110 and/or the like). The data 812 may include a controlchannel, such as a PDCCH. The reception module may provide the data 812to the scanning module 806 as data 814.

The scanning module 806 may scan candidate samples of the controlchannel to identify a relevant sample associated with the apparatus 802.For example, the scanning module 806 may scan or search using atop-to-bottom approach. The scanning module may provide data 816identifying the relevant sample to the decoding module 808.

The decoding module 808 may decode the relevant sample. For example, thedecoding module 808 may decode the relevant sample to obtain a downlinkgrant, a DCI, and/or the like. In some aspects, the decoding module 808may provide data 818 to the reception module 804 and/or the transmissionmodule 810 identifying the downlink grant, DCI, and/or the like. Thereception module 804 or transmission module 810 may receive data 812 ortransmit data 820 based at least in part on the data 818.

The apparatus may include additional modules that perform each of theblocks of the algorithm in the aforementioned flow chart of FIG. 7 . Assuch, each block in the aforementioned flow chart of FIG. 7 may beperformed by a module and the apparatus may include one or more of thosemodules. The modules may be one or more hardware components specificallyconfigured to carry out the stated processes/algorithm, implemented by aprocessor configured to perform the stated processes/algorithm, storedwithin a computer-readable medium for implementation by a processor, orsome combination thereof.

The number and arrangement of modules shown in FIG. 8 are provided as anexample. In practice, there may be additional modules, fewer modules,different modules, or differently arranged modules than those shown inFIG. 8 . Furthermore, two or more modules shown in FIG. 8 may beimplemented within a single module, or a single module shown in FIG. 8may be implemented as multiple, distributed modules. Additionally, oralternatively, a set of modules (e.g., one or more modules) shown inFIG. 8 may perform one or more functions described as being performed byanother set of modules shown in FIG. 8 .

FIG. 9 is a diagram 900 illustrating an example of a hardwareimplementation for an apparatus 802′ employing a processing system 902.The apparatus 802′ may be a UE (e.g., the UE 120).

The processing system 902 may be implemented with a bus architecture,represented generally by the bus 904. The bus 904 may include any numberof interconnecting buses and bridges depending on the specificapplication of the processing system 902 and the overall designconstraints. The bus 904 links together various circuits including oneor more processors and/or hardware modules, represented by the processor906, the modules 804, 806, 808, 810, and the computer-readablemedium/memory 908. The bus 904 may also link various other circuits suchas timing sources, peripherals, voltage regulators, and power managementcircuits, which are well known in the art, and therefore, will not bedescribed any further.

The processing system 902 may be coupled to a transceiver 910. Thetransceiver 910 is coupled to one or more antennas 912. The transceiver910 provides a means for communicating with various other apparatus overa transmission medium. The transceiver 910 receives a signal from theone or more antennas 912, extracts information from the received signal,and provides the extracted information to the processing system 902,specifically the reception module 804. In addition, the transceiver 910receives information from the processing system 902, specifically thetransmission module 810, and based at least in part on the receivedinformation, generates a signal to be applied to the one or moreantennas 912. The processing system 902 includes a processor 906 coupledto a computer-readable medium/memory 908. The processor 906 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 908. The software, whenexecuted by the processor 906, causes the processing system 902 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 908 may also be used forstoring data that is manipulated by the processor 906 when executingsoftware. The processing system further includes at least one of themodules 804, 806, 808, 810. The modules may be software modules runningin the processor 906, resident/stored in the computer readablemedium/memory 908, one or more hardware modules coupled to the processor906, or some combination thereof. The processing system 902 may be acomponent of the UE 120 and may include the memory 282 and/or at leastone of the TX MIMO processor 266, the RX processor 258, and/or thecontroller/processor 280. In some aspects, the processing system 902 maybe a component of the BS 110 and may include the memory 242 and/or atleast one of the TX MIMO processor 230, the receive processor 238,and/or the controller/processor 240.

In some aspects, the apparatus 802/802′ for wireless communicationincludes means for receiving a control channel that includes a pluralityof candidate samples having at least two aggregation levels; means forscanning a set of candidate samples, of the plurality of candidatesamples, to identify a relevant sample associated with the apparatus802/802′, wherein the scanning is performed on the set of candidatesamples in an order from a higher aggregation level of the at least twoaggregation levels to a lower aggregation level of the at least twoaggregation levels; and/or means for decoding the relevant sample. Theaforementioned means may be one or more of the aforementioned modules ofthe apparatus 802 and/or the processing system 902 of the apparatus 802′configured to perform the functions recited by the aforementioned means.As described supra, the processing system 902 may include the TX MIMOprocessor 266, the RX processor 258, and/or the controller/processor280. As such, in one configuration, the aforementioned means may be theTX MIMO processor 266, the RX processor 258, and/or thecontroller/processor 280 configured to perform the functions recited bythe aforementioned means.

Additionally, or alternatively, the aforementioned means may be one ormore of the aforementioned modules of the apparatus 802 and/or theprocessing system 902 of the apparatus 802′ configured to perform thefunctions recited by the aforementioned means. As described supra, theprocessing system 902 may include the TX MIMO processor 230, the receiveprocessor 238, and/or the controller/processor 240. As such, in oneconfiguration, the aforementioned means may be the TX MIMO processor230, the receive processor 238, and/or the controller/processor 240configured to perform the functions recited by the aforementioned means.

FIG. 9 is provided as an example. Other examples are possible and maydiffer from what was described in connection with FIG. 9 .

FIG. 10 is a flow chart of a method 1000 of wireless communication. Themethod may be performed by a base station (e.g., the BS 110 of FIG. 1 ,the apparatus 1102/1102′, and/or the like).

At 1010, the BS may generate at least one control signal for at leastone UE for transmission in a control channel. For example, the BS mayidentify the at least one UE based at least in part on the BS coveringthe at least one UE, based at least in part on the BS being a schedulingentity for the at least one UE, based at least in part on the BS havinga mmWave link with the at least one UE, and/or the like.

In some aspects, the control channel is associated with a plurality ofaggregation levels, and a highest aggregation level, of the plurality ofaggregation levels, spans an entirety of the control channel. Forexample, the BS may generate a control channel (e.g., a PDCCH) toprovide the control signal. The control channel may be associated with aplurality of aggregation levels. A highest aggregation level, of theplurality of aggregation levels, may span an entirety of the controlchannel.

At 1020, the BS may select at least one aggregation level, of aplurality of aggregation levels, for the at least one control signal tominimize gaps in the control channel. For example, the BS may select atleast one aggregation level for the at least one control signal. The BSmay select the at least one aggregation level to minimize gaps in thecontrol channel. For example, the BS may select a highest aggregationlevel that spans the entire control channel when the at least one UEincludes a single UE. Additionally, or alternatively, the BS may selecta same aggregation level for two or more different control signals tominimize the gaps, or may select different aggregation levels for two ormore different control signals to minimize the gaps.

At 1030, the BS may provide the control channel including at least onesample corresponding to the at least one control signal. For example,the BS may provide the control channel to the at least one UE. Thecontrol channel may include at least one sample corresponding to the atleast one control signal, and the at least one UE may search the controlchannel to identify relevant samples that are relevant to the at leastone UE.

Method 1000 may include additional aspects, such as any single aspect orany combination of aspects described below.

In some aspects, a highest aggregation level, of the plurality ofaggregation levels, spans an entirety of the control channel. In someaspects, a particular UE of the at least one UE is configured to receivea plurality of control signals, and the base station is configured toprovide a plurality of control signals associated with the at least oneaggregation level as part of the control channel. In some aspects, theat least one control signal includes at least one scheduling grant. Insome aspects, the at least one control signal includes a plurality ofcontrol signals, and wherein at least two control signals, of theplurality of control signals, are associated with different aggregationlevels. In some aspects, a sample of a higher aggregation level, of theplurality of aggregation levels, includes multiple, different samples ofa lower aggregation level of the plurality of aggregation levels. Insome aspects, at least two candidate samples of a same aggregation levelinclude different quantities of resource elements.

Although FIG. 10 shows example blocks of a method of wirelesscommunication, in some aspects, the method may include additionalblocks, fewer blocks, different blocks, or differently arranged blocksthan those shown in FIG. 10 . Additionally, or alternatively, two ormore blocks shown in FIG. 10 may be performed in parallel.

FIG. 11 is a conceptual data flow diagram 1100 illustrating the dataflow between different modules/means/components in an example apparatus1102. The apparatus 1102 may be an eNB (e.g., the BS 110). In someaspects, the apparatus 1102 includes a reception module 1104, anidentification module 1106, a generation module 1108, a selection module1110, and/or a transmission/provision module 1112.

The reception module 1104 may receive or determine data 1114 that is tobe provided to a UE 1150 (e.g., a UE 120 and/or the like), and mayprovide an indication of the data 1114 to the identification module 1106as data 1116. Based at least in part on the data 1114, theidentification module 1106 may identify the UE 1150 to receive at leastone control signal. The at least one control signal may include DCIbased at least in part on the data 1114. The identification module 1106may provide information 1118 to the generation module 1108 indicatingthat the scheduling grant is to be provided to the UE 1150.

The generation module 1108 may generate the at least one control signalfor the UE 1150 for transmission in a control channel (e.g., a PDCCH).The generation module 1108 may provide data 1120 to the selection module1110 identifying the at least one control signal. The selection module1110 may select at least one aggregation level, of a plurality ofaggregation levels, for the at least one control signal to minimize gapsin the control channel. The selection module 1110 may provide data 1122to the transmission/provision module 1112 identifying the controlchannel, as configured based at least in part on the at least oneaggregation level. The transmission/provision module 1112 may providethe control channel to the UE 1150 as signals 1124.

The apparatus may include additional modules that perform each of theblocks of the algorithm in the aforementioned flow chart of FIG. 10 . Assuch, each block in the aforementioned flow chart of FIG. 10 may beperformed by a module and the apparatus may include one or more of thosemodules. The modules may be one or more hardware components specificallyconfigured to carry out the stated processes/algorithm, implemented by aprocessor configured to perform the stated processes/algorithm, storedwithin a computer-readable medium for implementation by a processor, orsome combination thereof.

The number and arrangement of modules shown in FIG. 11 are provided asan example. In practice, there may be additional modules, fewer modules,different modules, or differently arranged modules than those shown inFIG. 11 . Furthermore, two or more modules shown in FIG. 1 may beimplemented within a single module, or a single module shown in FIG. 11may be implemented as multiple, distributed modules. Additionally, oralternatively, a set of modules (e.g., one or more modules) shown inFIG. 11 may perform one or more functions described as being performedby another set of modules shown in FIG. 11 .

FIG. 12 is a diagram 1200 illustrating an example of a hardwareimplementation for an apparatus 1102′ employing a processing system1202. The apparatus 1102′ may be an eNB (e.g., the BS 110 and/or thelike).

The processing system 1202 may be implemented with a bus architecture,represented generally by the bus 1204. The bus 1204 may include anynumber of interconnecting buses and bridges depending on the specificapplication of the processing system 1202 and the overall designconstraints. The bus 1204 links together various circuits including oneor more processors and/or hardware modules, represented by the processor1206, the modules 1104, 1106, 1108, 1110, 1112, and thecomputer-readable medium/memory 1208. The bus 1204 may also link variousother circuits such as timing sources, peripherals, voltage regulators,and power management circuits, which are well known in the art, andtherefore, will not be described any further.

The processing system 1202 may be coupled to a transceiver 1210. Thetransceiver 1210 is coupled to one or more antennas 1212. Thetransceiver 1210 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 1210 receives asignal from the one or more antennas 1212, extracts information from thereceived signal, and provides the extracted information to theprocessing system 1202, specifically the reception module 1104. Inaddition, the transceiver 1210 receives information from the processingsystem 1202, specifically the transmission/provision module 1112, andbased at least in part on the received information, generates a signalto be applied to the one or more antennas 1212. The processing system1202 includes a processor 1206 coupled to a computer-readablemedium/memory 1208. The processor 1206 is responsible for generalprocessing, including the execution of software stored on thecomputer-readable medium/memory 1208. The software, when executed by theprocessor 1206, causes the processing system 1202 to perform the variousfunctions described supra for any particular apparatus. Thecomputer-readable medium/memory 1208 may also be used for storing datathat is manipulated by the processor 1206 when executing software. Theprocessing system further includes at least one of the modules 1104,1106, 1108, 1110. The modules may be software modules running in theprocessor 1206, resident/stored in the computer readable medium/memory1208, one or more hardware modules coupled to the processor 1206, orsome combination thereof. The processing system 1202 may be a componentof the BS 110 and may include the memory 242 and/or at least one of theTX MIMO processor 230, the receive processor 238, and/or thecontroller/processor 240. In some aspects, the processing system 1202may be a component of the UE 120 and may include the memory 282 and/orat least one of the TX MIMO processor 266, the RX processor 258, and/orthe controller/processor 280.

In some aspects, the apparatus 1102/1102′ for wireless communicationincludes means for generating at least one control signal for at leastone user equipment (UE) for transmission in a control channel, whereinthe control channel is associated with a plurality of aggregationlevels; means for selecting at least one aggregation level, of theplurality of aggregation levels, for the at least one control signal tominimize gaps in the control channel; and/or means for providing thecontrol channel including at least one sample corresponding to the atleast one control signal. The aforementioned means may be one or more ofthe aforementioned modules of the apparatus 1102 and/or the processingsystem 1202 of the apparatus 1102′ configured to perform the functionsrecited by the aforementioned means. As described supra, the processingsystem 1202 may include the TX MIMO processor 230, the receive processor238, and/or the controller/processor 240. As such, in one configuration,the aforementioned means may be the TX MIMO processor 230, the receiveprocessor 238, and/or the controller/processor 240 configured to performthe functions recited by the aforementioned means.

Additionally, or alternatively, the aforementioned means may be one ormore of the aforementioned modules of the apparatus 1102 and/or theprocessing system 1202 of the apparatus 1102′ configured to perform thefunctions recited by the aforementioned means. As described supra, theprocessing system 1202 may include the TX MIMO processor 266, the RXprocessor 258, and/or the controller/processor 280. As such, in oneconfiguration, the aforementioned means may be the TX MIMO processor266, the RX processor 258, and/or the controller/processor 280configured to perform the functions recited by the aforementioned means.

FIG. 12 is provided as an example. Other examples are possible and maydiffer from what was described in connection with FIG. 12 .

It is understood that the specific order or hierarchy of blocks in theprocesses/flow charts disclosed is an illustration of exampleapproaches. Based upon design preferences, it is understood that thespecific order or hierarchy of blocks in the processes/flow charts maybe rearranged. Further, some blocks may be combined or omitted. Theaccompanying method claims present elements of the various blocks in asample order, and are not meant to be limited to the specific order orhierarchy presented.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” The word “exemplary” is used hereinto mean “serving as an example, instance, or illustration.” Any aspectdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other aspects. Unless specifically statedotherwise, the term “some” refers to one or more. Combinations such as“at least one of A, B, or C,” “at least one of A, B, and C,” and “A, B,C, or any combination thereof” include any combination of A, B, and/orC, and may include multiples of A, multiples of B, or multiples of C.Specifically, combinations such as “at least one of A, B, or C,” “atleast one of A, B, and C,” and “A, B, C, or any combination thereof” maybe A only, B only, C only, A and B, A and C, B and C, or A and B and C,where any such combinations may contain one or more member or members ofA, B, or C. All structural and functional equivalents to the elements ofthe various aspects described throughout this disclosure that are knownor later come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed by the claims. Moreover, nothing disclosed herein isintended to be dedicated to the public regardless of whether suchdisclosure is explicitly recited in the claims. No claim element is tobe construed as a means plus function unless the element is expresslyrecited using the phrase “means for.”

1. (canceled)
 2. An apparatus for wireless communication at a networkentity, comprising: one or more memories; and one or more processors,coupled to the one or more memories, configured to cause the networkentity to: provide a first downlink control information (DCI) for afirst user equipment (UE) using a particular aggregation level of aplurality of aggregation levels associated with a control channel,wherein the plurality of aggregation levels includes: a firstaggregation level that is a highest aggregation level of the pluralityof aggregation levels, and a second aggregation level that is lower thanthe first aggregation level, wherein a first candidate sample at thehighest aggregation level spans a region of a physical downlink controlchannel (PDCCH) payload region, wherein a second candidate sample at thesecond aggregation level spans a first portion of the region, wherein athird candidate sample at the second aggregation level spans a secondportion of the region, and wherein the particular aggregation level isthe second aggregation level; and provide a second DCI for a second UE.3. The apparatus of claim 2, wherein the plurality of aggregation levelsfurther includes a third aggregation level that is lower than the secondaggregation level.
 4. The apparatus of claim 3, wherein a fourthcandidate sample and a fifth candidate sample are at the thirdaggregation level.
 5. The apparatus of claim 4, wherein the fourthcandidate sample spans a third portion of the region, and wherein thefifth candidate sample spans a fourth portion of the region.
 6. Theapparatus of claim 5, wherein a sixth candidate sample is at the thirdaggregation level and spans a fifth portion of the region.
 7. Theapparatus of claim 3, wherein a first plurality of candidate samples atthe third aggregation level splits the region, wherein a first quantityof the first plurality of candidate samples at the third aggregationlevel is greater than a second quantity of a second plurality ofcandidate samples at the second aggregation level, and wherein thesecond plurality of candidate samples includes the second candidatesample and the third candidate sample.
 8. The apparatus of claim 2,wherein a combination of the second candidate sample and the thirdcandidate sample spans an entirety of the region.
 9. The apparatus ofclaim 2, wherein the first portion of the PDCCH payload region is halfof the region.
 10. The apparatus of claim 2, wherein the one or moreprocessors, to provide the second DCI, are configured to cause thenetwork entity to: provide the second DCI using the particularaggregation level.
 11. The apparatus of claim 2, wherein the one or moreprocessors, to provide the first DCI, are configured to cause thenetwork entity to: provide the first DCI using the first portion of theregion, and wherein the one or more processors, to provide the secondDCI, are configured to cause the network entity to: provide the secondDCI using the second portion of the region.
 12. The apparatus of claim2, wherein the plurality of aggregation levels further includes a thirdaggregation level that is lower than the second aggregation level, andwherein the one or more processors are further configured to cause thenetwork entity to: provide a third DCI for the first UE using the thirdaggregation level.
 13. A method of wireless communication performed at anetwork entity, comprising: providing a first downlink controlinformation (DCI) for a first user equipment (UE) using a particularaggregation level of a plurality of aggregation levels associated with acontrol channel, wherein the plurality of aggregation levels includes: afirst aggregation level that is a highest aggregation level of theplurality of aggregation levels, and a second aggregation level that islower than the first aggregation level, wherein a first candidate sampleat the highest aggregation level spans a region of a physical downlinkcontrol channel (PDCCH) payload region, wherein a second candidatesample at the second aggregation level spans a first portion of theregion, wherein a third candidate sample at the second aggregation levelspans a second portion of the region, and wherein the particularaggregation level is second aggregation level; and providing a secondDCI for a second UE.
 14. The method of claim 13, wherein the pluralityof aggregation levels further includes a third aggregation level that islower than the second aggregation level.
 15. The method of claim 14,wherein a fourth candidate sample and a fifth candidate sample are atthe third aggregation level.
 16. An apparatus for wireless communicationat a user equipment (UE), comprising: one or more memories; and one ormore processors, coupled to the one or more memories, configured tocause the UE to: receive a control channel that includes a plurality ofcandidate samples having a plurality of aggregation levels, wherein theplurality of aggregation levels includes: a first aggregation level thatis a highest aggregation level of the plurality of aggregation levels,and a second aggregation level that is lower than the first aggregationlevel, and wherein the plurality of candidate samples includes: a firstcandidate sample at the highest aggregation level spanning a region of aphysical downlink control channel (PDCCH) payload region, a secondcandidate sample at the second aggregation level spanning a firstportion of the region, and a third candidate sample at the secondaggregation level spanning a second portion of the region; and identifythe first candidate sample, the second candidate sample, or the thirdcandidate sample.
 17. The apparatus of claim 16, wherein the pluralityof aggregation levels further includes a third aggregation level that islower than the second aggregation level.
 18. The apparatus of claim 17,wherein a fourth candidate sample and a fifth candidate sample are atthe third aggregation level.
 19. The apparatus of claim 18, wherein thefourth candidate sample spans a third portion of the region, and whereinthe fifth candidate sample spans a fourth portion of the region.
 20. Theapparatus of claim 19, wherein a sixth candidate sample is at the thirdaggregation level and spans a fifth portion of the region.
 21. Theapparatus of claim 17, wherein a first plurality of candidate samples atthe third aggregation level splits the region, wherein a first quantityof the first plurality of candidate samples at the third aggregationlevel is greater than a second quantity of a second plurality ofcandidate samples at the second aggregation level, and wherein thesecond plurality of candidate samples includes the second candidatesample and the third candidate sample.
 22. The apparatus of claim 16,wherein a combination of the second candidate sample and the thirdcandidate sample spans an entirety of the region.
 23. The apparatus ofclaim 16, wherein the first portion of the PDCCH payload region is halfof the region.
 24. A method of wireless communication performed at auser equipment (UE), comprising: receiving a control channel thatincludes a plurality of candidate samples having a plurality ofaggregation levels, wherein the plurality of aggregation levelsincludes: a first aggregation level that is a highest aggregation levelof the plurality of aggregation levels, and a second aggregation levelthat is lower than the first aggregation level, and wherein theplurality of candidate samples includes: a first candidate sample at thehighest aggregation level spanning a region of a physical downlinkcontrol channel (PDCCH) payload region, a second candidate sample at thesecond aggregation level spanning a first portion of the region, and athird candidate sample at the second aggregation level spanning a secondportion of the region; and identifying the first candidate sample, thesecond candidate sample, or the third candidate sample.
 25. The methodof claim 24, wherein the plurality of aggregation levels furtherincludes a third aggregation level that is lower than the secondaggregation level.
 26. The method of claim 25, wherein a fourthcandidate sample and a fifth candidate sample are at the thirdaggregation level.
 27. The method of claim 26, wherein the fourthcandidate sample spans a third portion of the region, and wherein thefifth candidate sample spans a fourth portion of the region.
 28. Themethod of claim 27, wherein a sixth candidate sample is at the thirdaggregation level and spans a fifth portion of the region.
 29. Themethod of claim 25, wherein a first plurality of candidate samples atthe third aggregation level splits the region, wherein a first quantityof the first plurality of candidate samples at the third aggregationlevel is greater than a second quantity of a second plurality ofcandidate samples at the second aggregation level, and wherein thesecond plurality of candidate samples includes the second candidatesample and the third candidate sample.
 30. The method of claim 24,wherein a combination of the second candidate sample and the thirdcandidate sample spans an entirety of the region.
 31. The method ofclaim 24, wherein the first portion of the PDCCH payload region is halfof the region.